|LED display screen system protection and maintain tips|
The products involved in the led display system are treated with acid rain, salt spray, waterproof, moisture, dust, fire, corrosion, etc. Through the salt spray test, the test results show that the products meet the national industrial standards and meet the salt spray. The test requires that the screen be used for long periods of time even in maritime climate conditions.
Three precautions: All boards are treated with special electronic three-proof paint after production inspection, and coated with flame retardant materials to make them dust-proof, moisture-proof, anti-corrosive and flame-retardant.
The pixel and the module are sealed with an insulating rubber ring to prevent moisture from penetrating.
The exterior decoration of the screen is made of high-quality aluminum-plastic composite board with excellent corrosion resistance and high-corrosion resistance. The joints between the plates are tightly filled with high-quality weather-resistant glue.
The joint between the decoration and the module is filled with foam rods and filled with high-quality weather-resistant glue to prevent moisture from penetrating.
The protection level of all products is up to led display IP65 level before discharge.
1 temperature control and dehumidification
A smoke detector and a temperature sensor are installed inside the screen to connect to the PLC control system monitor screen. When the internal temperature of the screen is warmed up due to long-term operation or the humidity is high due to weather, the system can turn on the fan and air conditioner. In case of special circumstances, the PLC system can automatically cut off the screen power and send out an alarm signal.
2 Electrical safety
The measure taken in the area of electrical safety performance assurance is to configure the PLC controller. The power distribution cabinet is controlled by a PLC, and the display screen is turned on in several steps at startup to suppress the inrush current when the switching power supply is started. The PLC receives the system machine command to generate the action logic, and returns the logical state and fault information of each contact to the system. The network implements power supply loop control and monitoring of the system. The protection measures of the power distribution cabinet include over current, short circuit, open circuit, over voltage, under voltage, over temperature, smoke sensing, etc., and have fault indication. The network power supply protection device UPS has a power-off time of at least twenty minutes. In the event of a power failure, there is sufficient time for the system operator to perform the correct processing action.
In addition, a signal ground independent of the protection ground is required for use by the network system and the distributed control system. The lightning protection of the power grid relies on the on-site distribution system.
3 screen cooling system
Pay attention to the selection of components, such as power supply and driver IC, which can be used to work normally in a higher temperature range;
The drive control circuit uses a static small current drive IC;
The advanced PWM pulse width adjustment technology effectively improves the luminous efficiency of the screen and reduces the power consumption of the screen;
The use of a large number of low-power integrated circuits as the main body of the drive circuit not only effectively reduces the operating temperature of the IC, but also reduces the total power consumption of the system. “Safe and power saving” has become a major feature of Hongxiang Technology's display;
The driving circuit board adopts "four-layer board", which increases the flow area of the driving current, effectively disperses the driving current reasonably, and further reduces the working temperature;
The cooling fan of the screen DC power supply directly blows to the screen body, reducing the operating temperature of the light-emitting component and the driving IC;
The rear structure of the screen body is designed to meet the convection characteristics of the heat convection characteristics, ensuring smooth air circulation at the rear of the screen body and enhancing the heat dissipation capability of the screen body;
The decorative structure material with better thermal radiance is used to enhance the heat dissipation capability of the screen body;
Set up a temperature monitoring system, through the thermal sensor, the screen body has an over temperature automatic alarm and automatic adjustment function;
Combined with the temperature control system, a certain number of air conditioners are used to achieve rapid temperature adjustment.
4 lightning protection
Judging from the current use of lightning protection devices, lightning rods, mesh belts, and Faraday cages are effective in preventing buildings from being directly struck by lightning. However, in the process of guiding the lightning, the electromagnetic field generated by the lightning current left around has a great destructive effect on the electronic equipment. Therefore, the manufacturer uses a special lightning protection device to protect the power supply line and the signal line, thereby preventing the inductive lightning strike on the display. The influence and destruction of the screen electronic equipment, when the lightning strike occurs, the lightning protection equipment can quickly discharge to the ground, and the powerful current is introduced into the earth, thereby ensuring the LED display body and its accessory equipment are foolproof.
Since the led screen display is installed on the side of the building and within the lightning protection of the building, the display can be regarded as a powered device in the building.
The measure against lightning strikes is to connect the steel structure of the display to the main ribs of the building. The main ribs are generally used as lightning protection grounding poles. The anti-inductive lightning is installed with an (8/20us) power supply arrester on the upper part of the power distribution cabinet of the display. The grounding of the lightning arrester can be connected to the three-phase five-wire PE ground. Grounding is the key to lightning protection and is usually grounded. Use the PE phase copper bar in the power distribution cabinet as the grounding bar, connect the protective grounding wire PE of the power cable, the grounding wire of the switching power supply in the box, and the grounding wire of the power supply arrester to the grounding bar, and the grounding bar and the screen steel structure. connection. The grounding resistance is less than 1Ω.
5 Electromagnetic interference protection
All boards are coated with electromagnetic shielding materials to prevent the effects of electromagnetic interference signals on the control circuit.
6 noise reduction processing
Due to the noise brought by the medium and the quantization noise of the analog-to-digital conversion, the video display effect of the display screen is greatly affected, and certain noise reduction processing measures must be taken. Our company has developed an LED control system with recursive and median filtering functions using a large-scale programmable integrated circuit to better improve the viewing effect of full-color screen video images.